1. Field of the Invention
The present invention relates to video transcoding and, more specifically but not exclusively, to management of spatial resolution in compressed video bit-streams.
2. Description of the Related Art
This section introduces aspects that may help facilitate a better understanding of the invention(s). Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
Video transcoding is a process of converting a previously compressed video bit-stream into another compressed video bit-stream, e.g., with a different bit rate, a different frame rate, a different display format, and/or a different coding method. For example, video transcoding can be used to convert a video bit-stream encoded in one standard into a video bit-stream encoded in a different standard, with the initial and final standards selected from a set consisting of the H.26x and MPEG-z families of standards, where x=1, 3, 4 and z=1, 2, 4. Another important example of video transcoding is conversion of a compressed video bit-stream having one spatial resolution into a compressed video bit-stream having a different (typically lower) spatial resolution, without changing the standard. Other video-transcoding operations may include adding enhanced error resilience, inserting logos and watermarks, adjusting temporal resolution, etc. Video transcoding advantageously enables multimedia devices of diverse formats and capabilities to exchange video content on heterogeneous transport-network platforms, such as the Internet.
A video transcoder can be physically placed at a transmitter, a receiver, or an intermediate node in the network. In realizing a video transcoder, the computational complexity and picture quality are usually the two most-important concerns. Another important concern is the ability to provide video transcoding on the fly, e.g., with real-time speed and without video-flow interruptions. However, accommodating these and other pertinent concerns can be a significant challenge, e.g., due to relatively large and fast variability of the network-traffic load and available transmission bandwidths.